Valve mechanism for hydraulic units



March 13, 1951- w. H. WORTHINGTON ET AL 2,544,972

VALVE MECHANISM FOR HYDRAULIC UNITS Original Filed Aug. 4, 1944 22 INVENTORS WAYNE H. WORTHINGTON BY EMIL F. IRSA ATTORNEYS tion of constructions heretofore known, including that in our patent identified above.

Also illustrated schematically is a source of fluid pressure, here shown as a pump P having a fluid intake 24, connected to the reservoir (not shown) of the system, and a high-pressure conduit 26. The casing I9 is appropriately cored or otherwise provided with a high-pressure or supply passage 28 connected directly to the highpressure conduit 26. Within the casing I9, the high-pressure passage 28 is provided with two branches 39 and 32. The passage branch 39 opens through an outlet port or opening 34 to a vertical valve bore 36 in the casing I9. The passage branch 32 likewise opens to the valve bore 36, via an outlet port or opening 38. The 'bore 36 is enlarged annularly at 49 and 42, respectively, in alignment with the ports 34 and 38.

The casing I9 is hollow at 44 and thus communicates through the opening I2 to the reservoir of the system. The valve bore 36 opens upwardly through a discharge port 46 to this hollow portion 44, the latter providing, in effect, the reservoir or a part thereof. The port 46 is of the same diameter as the main part of the bore 36 so that a by-pass valve, designated generally by the numeral 48, may be freely axially reciprocal in the bore.

The by-pass valve member 48 is part of by-pass means including the by-pass valve, the bore 36, the ports 34, 38 and 46, and other ports to be presently described. This valve member is operable in the casing to control the position of the piston 29 in the cylinder I8. Manual control of the valve 48 is accomplished by means including a rockshaft 66, an operating arm 52 aflixed thereto, and a connecting'member 54 articulately connected at 56 to the arm 52. The rockshaft 59 may have connected thereto an operating lever 58, the specific details of which may be of any 'suitable design.

The valve member 48 includes a'first portion "69 and a second portion 62, both of which are preferably of the same diameter andboth of whichare slidably receivable in the bore 36. That portion of the valve 48 between the portion '69 and the connecting member 54 is reduced, as

at '64, to provide for discharge of fluid through "the passage branch 36, the port 34,- and the port "46 when the valve member is in the position illustrated. Another portion of the valve member is reduced at 66 between the portions 69 and 62, to provide for communicating the high-pressure passage 26 through the passage branch 32 and port 38 with a conduit 68 which is ultimately fluid-connectible to a motor or cylinder port I9. The port 79 is directly connected by a passage I2, bored or otherwise provided in the casing I9,

' which is in turn in communication with one end of the fluid motor I6 via a fluid passage or conduit I4. In an integral system of the type referred to, the passages or conduits'24, 26 and I4 would be cored in castings comprising integral or associated parts of the unit. For the present purposes, the schematic illustration is deemed suflicient to illustrate the relationship between of the bore designated by the numeral 89. The annular chamber I8 is further at times in fluidcommunication with another annular chamber 82 through a portion of the bore designated by the numeral 84. In the position of the valve 48 as shown, the chamber 82 substantially surrounds the lower valve portion 62, which portion is received in a bore portion indicated by the numeral 86. The bore portion 86 opens into an enlarged annular chamber 88 spaced axially below the annular chamber 92. Inasmuch as the annular chambers 49, 42, I8, 82 and 88 are coaxial on the axis of the bore 36, they are likewise coaxial with the motor port T9.

The lower end of the passage or conduit 68 communicates with the port I9 by means of a port 99 which is controlled by a check valve 92. Since the port I9 is at times fluid-connected to the high-pressure passage 28, the port 19 may be spoken'of as a discharge port through which fluid is transmitted or discharged to the motor I6, the port 19 being selectively utilized alternately with the discharge port 46 at the upper end of the valve bore, depending upon whether fluid is transmitted to the motor I6 or is merely circulated at no. appreciable pressure through the port 46 to .the reservoir.

The check valve 92 includes a first valve member 94 disposed coaxially with the by-pass valve 48 and slidably carried by a bearing 96. The check valve member 94 is drilled axially or otherwise formed hollow to receive a second check valve member 98, which has a stem I99 extending slidably through the check valve member 94 into proximity to the lower portion 62 of the valve 48.

Communication between the ports I9 and 99 is controlled mainly by the larger check valve member 94, which has a head I92 cooperative with a valve seat I94 between the ports 18 and 99. The lower portion of the bore provided in the check valve member 94 is enlarged to provide a chamber I96 which opens through the head I92 of the member 94 as a seat I98 for the head of the second valve member 98.

The bottom of the casing I9 is drilled in axial alignment with the valve bore 36 and is internally threaded to receive a plug H9 which serves to retain yieldable means, such as a compression spring II2, for holding the check valve 92 in closed position. It will be noted that the spring 2 acts against the headed end of the second valve member 98. Since this end of the valve member 98 seats on the seat I98 of the first or larger valve member 94, the same spring operates to hold the head I92 of the member 94 on the seat I94. Cooperation between the head I92 and seat I94 provides stop means for limiting movement of the member 94 toward the by-pass valve 48. Similarly, engagement between the head of the second valve member 99 and the seat I98 of the larger valve member 92 provides stop means for limiting movement of the valve member 94 away from the by-pass valve 48. Fluid passage means is provided between the conduit or passage 68 and the inner or smaller valve member 98, part of this means comprising a pair of orifices I I4 and the annular chamber I96 referred to above. This fluid passage means is closely adjacent the headed end of the valves 94 and 98 and is substantially Within the confines of the valve seat including the portions I94 and 99.

The valve casing or housing I9 is provided with a pressure-relief valve, designated generally first valve; member having fluid passages formed therein within the confines of said seat portion thereon to fluid connect said intermediate port with the space between said stem member and said first valve member, a second valve member on said stem member formed with a seat portion engageable with said first valve member to close one end of the space formed between said stem and first valve member, said second valve mem ber constituting a stop for limiting the movement of said first valve member away from said by-pass valve, yieldable means acting on said second valve member to maintain said two valve members in a seated relation, and said first valve member seated relative to said intermediate port, and means for reciprocating said by-pass valve to relativelycontrol the flow of fluid through said discharge and intermediate ports, said by-pass valve on movement thereof to engage and move said valve stem, providing for the opening of said second valve member prior to any opening move ment of sa d first valve member.

3. A valve mechanism for a hydraulic power unit including a casing formed with a high pressure fluid passage having a fluid discharge port at its terminal end and a fluid port intermediate its ends, said mechanism including a reciprocating by-pass valve for controlling the flow of fluid through said discharge port arranged in a coaxial relation with said intermediate port, a check valve for controlling the flow of fluid through said intermediate port having a stem member engageable by said by-pass valve, a first valve member mounted in a spaced relation about said stem member for movement axially thereof, a seat portion on said first valve member adapted for seating engagement with a seat portion formed about said intermediate port, said first valve member having fluid passages formed therein within the confines of said seat portion thereon to fluid connect said intermediate port with the space-between said stem member and said first valve member, means on one of the members for limiting the movement of said first valve member toward said by-pass valve, a second valve member.on-

said stem member formed with a seat portion tion on said first valve member adapted for seat-r ing engagement with a seat portion formed about said intermediate port, said first valve member having fluid passage means formed therein closely adjacent to said seat portion thereon to fluid connect said intermediate port with the space between said stem member and said first valve member, means on one of the members for limiting the movement of said first valvemember toward said by-pass valve, a second valve mem: her on said stem member formed with a seat portion engageable with said first valve member to close one end of the space formed between v said stem and first valve member, said second engageable with said first valve member to close one end of the space formed between said stem and first valve member, said second valve'inember constituting a stop for limiting the movement of said first valve member away from said bypass valve, yieldable means acting on said second valve member to maintain said two valve members in a seated relation, and said first valve member seated relative to said intermediate port, and means for reciprocating said by-pass valve to relatively control the flow of fluid through said discharge and intermediate ports, said by-pass valve on movement thereof to engage and move said valve stem, providing for the opening of said second valve member prior to any opening movement of said first valve member.

' 4. A valve mechanism for a hydraulic power unit including a casing formed with a high pressure fluid passage having a fluid discharge port at its terminal end and a fiuid port intermediate its ends, said mechanism including a reciprocating by-pass valve for controlling the flow of fluid through said discharge port arranged in a coaxial relation with said intermediate port, a check valve for controlling the flow of fluid through said intermediate port having a stem member engageable by said by-pass valve, a first valve member mounted in a spaced relation about said stem member for movement axially thereof, a seat pervalve member constituting a stop for limiting the movement of said first valve member away from said by-pass valve, yieldable means acting on said second valve member to maintain said two valve members in a seated relation, and said first valve member seated relative to said intermediate port, and meansfor reciprocating said by-pass valve to relatively control the flow of fluid through said discharge and intermediate ports, said 'by-pass valve on movement thereof to engage and move said valve stem, providing for the opening of said second valve member prior to any opening move ment of said first valve member.

5. A valve mechanism for a hydraulic power unit including a casing formed with a high pressure fluid passage having a fluid discharge port at its terminal end and a fluid port intermediate its. ends, said mechanism including a reciprocating by-pass valve for controlling the flow of fluid through said discharge port arranged in a coaxial relation with said intermediate port, a check valve for controlling the flow of fluid through said intermediate port having a stem member engageable by said by-pass valve, a first valve member mounted in a spaced relation about said stem member for movement axially thereof, a seat portion on said first valve member adapted for seating engagement with a seat portion formed about said intermediate port, said first valve member having fluid passage means formed therein closely said stem and first valve member, means on one of said members constituting a stop for limiting the movement of said first valve member away from said by-pass valve, yieldable means acting on said second valve member to maintain said two valve members in a seated relation, and said first valve member seated relative to said intermediate port, and means for reciprocating said by-pass valve to relatively control the flow of fluid through said discharge and intermediate ports, said by-pass valve on movement thereof to engage and move said valve stem, providing for the opening of said second valve member prior to any opening movement of said first valve member.

6. A valve mechanism for a hydraulic power unit including a casing formed with a high pressure fluid passage having fluid inlet port means and fluid discharge port means, said casing further having a fluid port communicable with said passage intermediate the inlet port means and the discharge port means, said mechanism ineluding a reciprocally movable by-pass valve for controlling the flow of fluid through the discharge port means, a check valve for controlling the flow of fluid through said intermediate port arranged in coaxial alinement with said by-pass valve, said check valve including a pair of cooperating valve members relatively arranged and constructed to close said intermediate port, with one of said valve members adapted to be opened relative to the second one of said valve members to partially open said intermediate port, means acting on said one valve member to yieldably maintain said two valve members in closed position, and means on said check valve engageable with said by-pass valve, on movement of said bypass valve in one direction to open said discharge port means, such that said one valve member is opened prior to any opening movement of said second valve member.

7. For a hydraulic power unit having a casing provif ed with a valve bore, a motor port coaxial with one end of the valve bore, fluid passage means connected between the valve bore and the motor port, and an exhaust port communicable with the valve bore: valve mechanism comprising first valve means for controlling communication between the passage means and the exhaust port, including a valve selectively shiftable axially in a first direction in the valve bore to eilect communication between the Dassage means and the exhaust port, or shiftable axially in the opposite or second direction to block off the passage means from the exhaust port; second valve means for controlling flow of fluid to or from the passage means and through the motor port, including a dual check valve coaxial with the first valve means and having a pair of cooperating valve members relatively arranged and constructed to normally close the motor port, one of said valve members being movable relative to the other to partly open the motor port; means acting on said one valve member to yieldably maintain both valve members in closed position with respect to the motor port; and means on the second valve means engageable by the 'means for controlling communication between thepassage means and the valve bore, including'ja valve selectively shiftable axially in a first direction in the valve bore to efiect communication between the passage means and the valve bore, or shiftable axially in the opposite or seeond direction to block off the passage means from thevalve bore; second valve means for controlling flow of fluid to or from the passage means and through the port, including a dual check valve coaxial with the first valve means and having a pair of cooperating valve members relatively arranged and constructed to normally close the port, one of said valve members being movable relative to the other to partly open the port; means acting on said one valve member to yieldably maintain both valve members in closed 7 position with respect to the port; and means on the second valve means engageable by the first valve means, upon movement of said first valve means in the aforesaid first direction, for effecting opening of said one valve member prior to and followed by opening of the other of the valve members.

WAYNE H. WORTHINGTON. EMIL F. JIRSA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,459,613 Baker Jan. 18, 1949 

